It is difficult to study the relation of diet to cancer in the USA because of uniformity of dietary practices. Seventh-Day Adventists (SDAs) are a conservative religious group who do not smoke or drink by church proscription, and about 50% of them do not use meat or coffee. SDAs are very health oriented, and many of them abundantly use whole grains and other unrefined foods. For most cancer sites unrelated to smoking, previous studies have demonstrated that mortality rates in SDAs are about 70% of general population rates. This ongoing prospective study seeks to confirm these mortality differences with incidence data and to determine the specific component(s) of the SDA lifestyle which account for the low risk of non-smoking-related cancers in SDAs. Detailed demographic and lifestyle characteristics of 67,000 California SDAs over age 25 will be collected. For a 5-year perod, all deaths and new cancer cases will be ascertained via annual contacts and review of hospital records for reported hospitalizations. Detailed characteristics and cancer incidence and survival rates of SDAs will be compared to a general population sample. Furthermore, we will be able to compare risk of major cancer sites between subgroups of SDAs with different degrees of adherence, or duration of exposure, to various habits unique to SDAs (i.e. lifetime vegetarians vs heavy meat consumers, etc.).